This invention generally relates to navigation or route guidance systems and, more particularly, to a system having a zoomed maneuver instruction view which provides a magnified view of a complex maneuver to provide clear and detailed instructions through the complex maneuver.
Navigation systems generally provide a recommended route to a desired destination. Generally, the desired destination is selected from a large database of roads stored in a mass media storage, such as a CD ROM, which includes the roads in the area to be traveled by the user. If the navigation system is installed in a vehicle, the starting point is typically associated with the vehicle position and can be input to the navigation system by an associated position determining system that usually includes a GPS (Global Positioning System) receiver.
The navigation system determines a route to the destination utilizing an algorithm well-known to those in the art and currently in use in many navigation systems. Usually there are many potential routes between the selected starting point and the desired destination. Typical navigation systems select a recommended route based upon certain xe2x80x9ccostxe2x80x9d values associated with each segment of road in the road database. These cost values include the length of the road segment and the estimated time of travel through the road segment. The navigation system selects the potential route with the lowest total cost to be the recommended route. Depending upon the predetermined algorithm of the navigation system, the navigation system will recommend the route with the shortest total length, the lowest total time, or some weighted average of length and time.
The recommended route is then displayed to the user as a map showing the vehicle, the desired destination and highlighting the recommended route. Preferably, if the navigation system is installed in a vehicle, the navigation system displays the current position of the vehicle and provides visual turn-by-turn instructions to the driver, guiding the driver to the selected destination.
The turn-by-turn instruction is typically selected from a database of predefined maneuver instructions such as a generic left-turn instruction, a right-turn instruction straight-ahead instruction or the like. However, the particular upcoming maneuver may not be provided in the maneuver instruction database. This may be confusing to the driver as the driver may have trouble identifying the generic instructed maneuver with the surroundings. This is particularly troubling in a highly congested and road intense environment such as a city.
It is thus desirable to provide a system for projecting definite maneuver instructions that accurately depict the vehicle surroundings and enhance the ability of a driver to correctly perceive the maneuver instruction.
In general terms, this invention provides a zoomed maneuver instruction view which provides a magnified view of a map display view.
The navigation system generally includes a database of a plurality of roads, a position determining system, an input device, and a route determination system. The position determining system determines a position of the vehicle relative to the plurality of roads. The user selects a destination from the database with the input device. The navigation system then calculates and displays a recommended route directing the driver of the vehicle to the desired destination. As the vehicle approaches an upcoming maneuver the display magnifies the large-scale map display view to provide a zoomed maneuver instruction view.
During many simple maneuvers, such as an individual left or right turn, a single maneuver instruction representation is displayed in a known manner. The maneuver instruction illustrates the upcoming maneuver to be performed along the recommended route to the destination. However, in some instances a user may be required to perform a complex or unusual maneuver to continue along a recommended route. Such complex maneuvers are typical in metro areas and may lead a user to incorrectly perform the maneuver. When such a maneuver is required the present invention switches to a zoomed maneuver instruction view which displays a magnified view of the complex maneuver.
Display of the zoomed maneuver instruction view is preferably related to the complexity of the road segments adjacent the upcoming maneuver. Each road segment and node are commonly stored within the database in a compressed or short-hand format to save space. Typically, the beginning and ending latitude and longitude (hereafter lat/long) point is the node which connects one segment to another road segment. The node being the ending lat/long point for the first road segment and also the beginning lat/long point for a second road segment. The database is therefore composed of a simple list of segments and associated beginning and ending lat/long points. This is effective for straight road segments. To store a non-straight road segment, a shape point is added between the beginning and ending lat/long points. Each shape point is preferably related back to the previous shape point. A first shape point is stored within the database as a lat/long point relative to the beginning lat/long point.
In one disclosed embodiment, the compressed road segment storage within the database allows the CPU to determine the complexity of any road segment. When the CPU identifies a complex road segment along the recommended route, the display switches to the zoomed maneuver instruction view.
In one embodiment, the zoomed maneuver instruction view is displayed if more than N numbers of shape points are within a predetermined distance along the recommended route. In another embodiment, the zoomed maneuver instruction view is displayed if the recommended route includes an upcoming complex maneuver adjacent a road segment with more than N number of shape points.
The zoomed maneuver instruction view is a magnified view of the map display view. Preferably, the CPU will continue to magnify the complex maneuver in the zoomed maneuver instruction view as the vehicle and associated vehicle icon progresses through the complex maneuver. When the complex maneuver completely fills a border within the display, the CPU will no longer zoom in on the complex maneuver in the zoomed maneuver instruction view. The zoomed maneuver instruction view will be maintained at this magnification as the vehicle icon progresses through the complex maneuver. The user can therefore better identify the relative position of the vehicle as vehicle icon progresses toward the next upcoming maneuver of the complex maneuver.
The user is thereby provided with clear instruction through the complex maneuver and is less likely to incorrectly perform the maneuver. This is particularly advantageous in a highly congested or road intense environment such as a city.